I think there are two possibilities:
1) The ice ages have suddenly returned: sea level has dropped 300 feet due to shift of water from the oceans into the newly nascent glaciers.
2) The mother of all tsunamis is approaching! Flee! Flee for your lives!
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"...far better it is to dare mighty things, to win glorious triumphs even though checkered by failure, than to rank with those poor spirits who neither enjoy much nor suffer much, because they live in the gray twilight that knows neither victory nor defeat."
- Theodore Roosevelt,
speech before the Hamilton Club, Chicago, April 10, 1899